transit in beijing from Helsinki

I am coming in to Beijing the 6th of September from Helsinki Finland at 06.55 local time. The 7th of september i have a confirmed ticket from Beijing to frankfurt at 10.40 in the morning local time. I have requested a ticket going directly to copenhagen from beijing at 14.40 the 7th as well as my final destination will be copenhagen. This plane is quite full so i am on the waiting list. If i understand everything i don't need a visa. When i am in Beijing may i change my flight going directly to copenhagen or do i need to stick with the flight that i have to frankfurt the 7/9??